After God destroyed His world by water, making a fresh start with Noah
and his family, God told Noah,

“Every moving thing that lives shall be food for you. Like plant
vegetation [which I permitted to Adam], I have now given you
everything. ... Only of the blood of your own lives will I demand
an account.” (Gen. 9:3,5)

Up until this point, humanity was expected to be vegetarian. But
after Noah and his family left the ark, God allowed them to eat
everything — except other people. Why was permission to eat animals given at this time?

Temporary Allowance

Given the violence and depravity of the
generation of the Flood, it was necessary to make allowances for
humanity’s moral frailty. If mankind was still struggling with
basic moral issues — such as not murdering his fellow human — what
point was there in frustrating him with additional prohibitions on
less self-evident issues?

After the Flood, God lowered the standards of morality and justice He
expected of humanity. We would no longer be culpable for slaughtering
animals; we would only be held accountable for harming
other human beings. Then our moral sensibilities, which had become
cold and insensitive in the confusion of life, could once again
warm the heart.

If the prohibition against meat had remained in force, then,
when the desire to eat meat became overpowering, there would be
little distinction between feasting on man, beast, and fowl. The
knife, the axe, the guillotine, and the electric pulse would cut
them all down, in order to satiate the gluttonous stomach of
“cultured” man. This is the advantage of morality when it is
connected to its Divine Source: it knows the proper time for each
objective, and on occasion will restrain itself in order to conserve
strength for the future.

In the future, this suppressed concern for the rights of animals
will be restored. A time of moral perfection will come, when “No
one will teach his neighbor or his brother to know God — for all
will know Me, small and great alike” (Jeremiah 31:33). In that era
of heightened ethical awareness, concern for the welfare of animals
will be renewed.

Preparing for the Future

In the interim, the mitzvot of the Torah prepare us for this
eventuality.

The Torah alludes to the moral concession involved in eating meat,
and places limits on the killing of animals. If “you desire to eat
meat,“ only then may you slaughter and eat (Deut. 12:20). Why
mention the “desire to eat meat"? The Torah is hinting: if you are
unable to naturally overcome your desire to eat meat, and the time
for moral interdiction has not yet arrived — i.e., you still
grapple with not harming those even closer to you (fellow human
beings) — then you may slaughter and eat animals.

Nonetheless, the Torah limits which animals we are allowed to eat,
only permitting those most suitable to human nature. The laws of
shechitah (ritual slaughtering) restrict the manner of killing
animals to the quickest and most humane. With these laws the Torah
impresses upon us that we are dealing with a living creature, not
some automaton devoid of life. And after slaughtering, we are
commanded to cover the blood, as if to say, “Cover up the blood!
Hide your crime!”

These restrictions will achieve their effect as they educate the
generations over time. The silent protest against animal slaughter
will become a deafening outcry, and its path will triumph.